Adjustable edge protection auxiliary accessory

An outer bracket of an adjustable bracket comprises an outer clamping plate and an outer connecting piece, an inner bracket comprises an inner clamping plate and an inner connecting piece, the outer clamping plate and the inner clamping plate are vertically arranged in the left-right direction and are arranged at intervals in the front-back direction, and the outer connecting piece and the inner connecting piece are arranged in the front-back direction. The right end of the outer clamping plate and the right end of the inner clamping plate are connected with the front end of the outer connecting piece and the rear end of the inner connecting piece respectively, the inner connecting piece is movably inserted into an inserting groove in the rear end of the outer connecting piece in the front-back direction, and the fixing piece transversely penetrates through the inserting groove, is meshed with the side wall of the inserting groove in a threaded mode and abuts against the inner connecting piece. The screw is a